10 results about "Total bacterial count" patented technology

The invention belongs to the technical field of food science, and particularly relates to a combined fresh-keeping method for improving the quality of raw milk and application of the combined fresh-keeping method. The total number of bacterial colonies, coliforms and psychrophilic bacteria are reduced through the high-density carbon dioxide and 75 MPa dynamic high-pressure microjet treatment; furthermore, near-freezing-point storage is more beneficial to slowing down the growth of microorganisms in the raw goat milk and the raw camel milk, the synergistic treatment effect of the two technologies is superior to that of the single technology, and the effect on the raw goat milk and the raw camel milk is superior to that of the raw cow milk. The combined technology can effectively inhibit the growth of putrefying bacteria and delay the spoilage of the raw milk, can maintain the protein structure to the maximum extent, and has a remarkable industrial application prospect.

This invention belongs to the field of functional food processing and provides a method for preparing aronia berry juice based on ultra-high pressure-ultrasound treatment. The invention uses the total polyphenol fraction B1 of aronia berry and plant protein to prepare a polyphenol-protein graft polymer via enzymatic grafting. Under specific pH, ionic strength, and ultrasonic conditions, the polymer self-assembles to form polyphenol-protein nanomicelles with a particle size of 50-150 nm. After being added to the aronia berry juice, it undergoes cold sterilization through a combination of high hydrostatic pressure and ultrasound treatment, constructing a stable polyphenol-rich interfacial shell structure. The finished juice retains at least 80% of the total polyphenols and has a total bacterial count of less than or equal to 10 CFU / mL after 90 days of storage at 4℃. This achieves multiple synergistic effects, including efficient polyphenol encapsulation, enhanced antioxidant and antibacterial activity, and improved physical stability. It solves the problems of increased viscosity and deteriorated taste caused by high polyphenol loading, as well as the destruction of active ingredients by heat sterilization, and has broad application value.

The invention discloses a pipeline microbial corrosion risk dynamic monitoring method which comprises the following three steps: S1, continuously collecting a pipeline water sample for multiple times, and carrying out viable bacteria qPCR analysis to obtain water sample microbial activity mu in different periods; the time interval between two times of collection of the pipeline water sample is 7-30 days, and the number of times of continuous collection of the pipeline water sample is not less than 3; s2, collecting the pipe wall sediment sample for qPCR analysis while collecting the pipeline water sample each time, and obtaining the total bacterial count of the pipe wall sediment in different periods; and S3, analyzing the variation trend of the dynamic data of the viable bacteria in the water sample and the dynamic data of the total bacterial count of the pipe wall sediment along with time, and evaluating the microbial corrosion risk condition in the pipeline. According to the method disclosed by the invention, the microbial corrosion risk in the pipeline is evaluated by defining the microbial activity index mu in a water sample, combining with the total bacterial count of pipe wall sediments and analyzing the change trends of the two parameters in a long-term monitoring process, so that the crossing from microbial quantity detection to microbial corrosion risk evaluation is realized.

This invention discloses a colorimetric diluent for the determination of microorganisms in food and its preparation method. The colorimetric diluent comprises sterile physiological saline and Brilliant Blue FCF at a final concentration of 0.0001%~0.1%. By adding a trace amount of food-grade blue pigment to the diluent, a clear blue color is achieved, allowing operators to visually judge the mixing state of the sample and diluent through the uniformity of the blue color, thus visualizing the series of dilution processes. This invention also discloses the preparation method of the colorimetric diluent and its application in the determination of total bacterial count. Experimental verification shows that the colorimetric diluent has no significant effect on the growth of common food microorganisms, does not affect the coagulation performance of PCA medium, and is fully compatible with the testing procedures of the national standard GB 4789.2-2022. This invention is low-cost, easy to operate, and can effectively reduce operator variability, making it particularly suitable for teaching and training, grassroots quality inspection training, and microbiological testing in standardized laboratories, with good prospects for industrial application.

The application discloses a device and method for rapidly determining total number of bacteria based on multi-wavelength reflection spectrum, which comprises: a light emitting element for emitting a continuous light beam; a monochromator arranged in the emission direction of the light beam for separating the light beam into monochromatic light of different wavelengths; an integrating sphere for receiving the monochromatic light separated by the monochromator and converging the diffused monochromatic light; a constant temperature element arranged in the integrating sphere for keeping the standard sample at constant temperature, the diffused reflection being generated after the monochromatic light irradiates the constant temperature standard sample; a photoelectric conversion element connected with the integrating sphere for converting the optical signal into an electrical signal; and an oscilloscope connected with the photoelectric conversion element for reading, calculating and recording the electrical signal conducted by the photoelectric conversion element. The application solves the technical problem that the existing detection method has a large error in detection result due to the size of bacteria individuals, the state of the sample and the color difference, so as to achieve the purpose of rapidly and accurately determining the total number of bacteria.

The invention belongs to the field of functional food processing, and provides aronia fruit juice based on ultrahigh pressure-ultrasonic treatment and a preparation method of the aronia fruit juice. The preparation method comprises the following steps: preparing a polyphenol-protein grafted polymer from aronia total polyphenol fraction B1 and vegetable protein through enzymatic grafting, carrying out self-assembly under specific pH value, ionic strength and ultrasonic conditions to form polyphenol-protein nano-micelles with the particle size of 50-150nm, adding the polyphenol-protein nano-micelles into aronia juice, and carrying out high hydrostatic pressure and ultrasonic synergistic treatment to realize cold sterilization. And a stable polyphenol-rich interface shell structure is constructed. When the finished fruit juice is stored for 90 days at 4 DEG C, the total polyphenol retention rate is larger than or equal to 80%, the total bacterial count is smaller than or equal to 10 CFU / mL, multiple synergy of efficiently embedding polyphenol, enhancing antioxidant activity and antibacterial effect and improving physical stability is achieved, the problems that viscosity is increased and taste is deteriorated due to introduction of high-load polyphenol and active ingredients are damaged due to thermal sterilization are solved, and the fruit juice is suitable for industrial production. And the method has wide application value.

The invention relates to a chicken fresh-keeping treatment method based on natural acid preservation, which comprises the following steps of: washing chicken with sterile ice water, and draining water on the surface; the surface of chicken is coated with a preservative solution with compound acid composed of citric acid and tartaric acid as well as clove extract, rosemary extract and tea polyphenol as active ingredients, and the compound acid is composed of citric acid and tartaric acid according to the mass ratio of (5-6): (3-4). According to the chicken preservation method, first-step preservation treatment is carried out through acid, then the preservative is sprayed for second-time preservation treatment, and in the preservative, the solubility of active ingredients and the covering uniformity of the active ingredients on the surface of the chicken are improved, so that the preservative performance of the chicken is remarkably improved, the shelf life of fresh chicken breast is prolonged, and the quality of the chicken breast is improved. After the chicken is preserved for 7 days at 4 DEG C, the total colony count of the chicken is as low as 3.2 log CFU / g, the MDA content is 0.12 mg / kg, the TVB-N content is 7.32 mg / 100g, and the water content of the chicken is still kept to be 74% or above.

The present application relates to the field of non-destructive detection of fish freshness, and particularly relates to a method for evaluating the freshness quality of ice-fresh big yellow croaker by using bioimpedance technology. The method for evaluating the freshness quality of ice-fresh big yellow croaker by using bioimpedance technology comprises the following steps: S1, immediately killing and processing fresh and healthy farmed big yellow croaker after being captured, and then storing the big yellow croaker in ice; S2, measuring the back and abdominal muscle bioimpedance values of the ice-fresh big yellow croaker in S1 at a frequency of 2 kHz or 100 kHz by using an impedance analyzer; S3, substituting the bioimpedance values Z 2kHz or Z 100 kHz measured in S2 into a big yellow croaker impedance and each quality change prediction model to calculate the values of key components and freshness indexes, wherein the key components include protein, fat and moisture, and the freshness indexes include color difference, pH, water activity, juice loss rate and total bacterial count; and S4, directly using the calculated values to replace the measured values to evaluate the fish body quality.

This invention provides a synergistic compound spray of lactic acid and acetic acid and its application in the preservation of chilled fresh lamb. The compound spray is composed of an aqueous solution of lactic acid and an aqueous solution of acetic acid. The mass fraction of lactic acid in the aqueous solution is 0.4-0.6%, and the mass fraction of acetic acid in the aqueous solution is 0.2-0.3%. The volume ratio of the two is 2:7 to 5:7. This invention also provides a corresponding method for preserving chilled fresh lamb: the compound spray is evenly sprayed onto the surface of the chilled lamb, which is then air-dried, packaged, and refrigerated. Experiments have confirmed that the combination of lactic acid and acetic acid in the compound spray agent of this invention exhibits a synergistic effect, with a combined antibacterial concentration index of 0.375. It can effectively inhibit the total bacterial count and coliform growth at low concentrations, delay the accumulation of volatile basic nitrogen, stabilize the pH, color, texture and sensory quality of meat products, avoid meat quality deterioration caused by high concentrations of single organic acids, and extend the shelf life of chilled fresh lamb at 4°C from 6 days to 10 days. It is safe and reliable and suitable for long-distance cold chain distribution and industrial applications.

This invention discloses a method for preparing a strain of Lactobacillus saccharidus and its application in the preservation of chilled fresh meat, including the following steps: Step (1) Initial screening: Take 1.0 g of environmental sample, add 9 mL of sterile physiological saline, shake at 37℃ and 200 r / min for 30 min, sonicate for 10 min, then serially dilute to 10⁻⁴-10⁻⁶, take 100 μL and spread it on MRS solid medium, incubate at 37℃ for 48 h, pick single colonies and purify 3 times; Step (2) Antibacterial screening: Use 8 strains of putrefactive bacteria such as Enterobacter and Escherichia coli as indicator bacteria. The preparation method of this Lactobacillus saccharidus strain is based on natural sources, ensuring high safety and making it a suitable alternative to chemical preservatives. It exhibits significant inhibitory effects on major spoilage bacteria (such as Pseudomonas and Enterobacteriaceae) and pathogenic bacteria in chilled meat. Its low-temperature resistance (4℃) and acid and alkali resistance make it suitable for the storage environment of chilled meat. After application, it can reduce the total bacterial count, TVB-N content, pH value, and drip loss rate, delay color changes, and effectively extend the shelf life of chilled meat.